Travel discussion for St. John
Prior to our last trip I bought some compression bags at REI. They're heavy-duty plastic with one-way valves at one end; you pack stuff in them and then just roll to squeeze out the air. They helped reduce my stuff by about 40%. (I packed my clothes in a smaller one, and we brought 4 beach towels which I packed in a large one.) It gives you more space in your bag, plus they'll keep moisture out (if something goops out in your suitcase, like lotion, it won't get on clothing in the compression bag) or keep moisture in (if you have to pack wet stuff because you got in one last snorkel trip on your way to the airport, you can pack those in the compression bag to keep your other stuff dry.) I was able to get by with one carry on for 10 days.